1.普通方法

#include<iostream>
#include<string> 
using namespace std;

int howLong(string s1){
	int m=s1.length();
	return m;
}

int main(int argc,char* argv[]){
    char aa[]="hijfasddasfasfasds";
    string s1=aa;
	int result=howLong(s1);
	int result2=howLong(aa);//这个方法也行 
	cout<<"该字符串长度为1:"<<result<<endl;
	cout<<"该字符串长度为2:"<<result2<<endl;
	return 0;
}